System and method for automating or metering fluid recovered at a well

ABSTRACT

Disclosed herein are methods, apparatus and systems for automating or metering fluid recovered at a well. According to one example, a system is described for automating the fluid recovery of oil wells using a pump jack or oil extractor. A communications device is installed with each system to allow remote bi-directional communications to monitor, control, and diagnose problems with the device or system.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from U.S. Provision ApplicationSerial No. 60/394,292 filed on Jul. 8, 2002 entitled “System and Methodfor Automating or Metering Fluid Recovered at a Well.”

FIELD OF THE INVENTION

[0002] The present system and method relates to an automatic fluidrecovery system, particularly for recovery systems used for recoveringoil and gas from wells. The system at the well may be monitored andcontrolled locally or remotely. The amount of fluid recovered at a wellis metered at the well.

BACKGROUND

[0003] Wells such as oil and gas wells are often located in remotelocations. Recovery devices such as pump jack are used to recover oilfrom the well and pump it to a storage tank. Typically, the tank isconnected to several wells by pipelines/flow lines that areinterconnected together. In the case of oil fields where water is oftenpumped with the oil, separator tanks are used to separate the oil fromthe water. The oil collected is then sold to refineries. Operation ofthese field devices is typically by connecting the device to a localpower supply and then turning on the motor. Maintenance requiresvisiting the site and viewing the operation of the device. If problemsoccur at the well or if adjustments are necessary after the scheduledmaintenance visit, it will have to wait until the next visit to bediscovered and corrected. Generally, determining the amount of oil orgas produced at a well is done by measuring the level of oil or gas inthe collection tank. If there is more than one well feeding the tank,determining the amount of oil or gas retrieved by any individual well isproblematic

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The foregoing and other objects and advantages of the inventionwill become clearer with reference to the following detailed descriptionas illustrated by the drawings in which:

[0005]FIG. 1 is a schematic diagram of a recovery system having acontrol module for automating the recovery of fluid from a well by arecovery device and for measuring the amount of fluid recovered at thatwell by a meter.

[0006]FIG. 1A is a schematic diagram of the recovery system of FIG. 1alternatively illustrating the control module as an integrated part ofthe recovery device.

[0007]FIG. 1B is a schematic diagram of the oil recovery system of FIG.1 alternatively illustrating the control module as an integrated part ofthe meter.

[0008]FIG. 2A is a schematic diagram of a tank meter used to measurefluid recovered by the recovery device.

[0009]FIG. 2B is a schematic of an alternative metering system for anoil extractor.

[0010]FIG. 2C is a flow diagram example illustrating automatic controlof a control module for automatically metering the volume of fluidrecovered by an oil extractor.

[0011]FIG. 3A is a flow diagram example illustrating control by thecontrol module for automating a recovery cycle.

[0012]FIG. 3B is a flow diagram of another example illustrating controlby the control module for automating a recovery cycle for a pump jack.

[0013]FIG. 4 is a flow diagram example for tuning a recovery cycle.

[0014]FIG. 5 is a schematic diagram used to illustrate a system ofrecovery devices connected to a storage tank.

DETAIL DESCRIPTION OF THE DISCLOSURE

[0015] The present disclosure provides a way of automating the fluidrecovery process at a well and because the system described below isrelatively inexpensive, it is particularly useful at low margin oilwells known as stripper wells. Stripper wells are low tier, lowproducing wells often yielding up to 5 barrels of oil a day. Byautomating the recovery process at each well, other benefits can berealized. For example, as will be discussed in more detail below, onebenefit is the ability to automatically discover the recovery rate ofoil in the well and tune the recovery of oil at that rate. This wouldsignificantly reduce the cost of oil recovery, both in expense tooperate the recovery device and maintenance to keep it operating.Another benefit is the ability to precisely measure the amount of oilrecovered at each well. Each well has its own recovery characteristic.By metering the amount of oil recovered at each well a history ofrecovery can be developed for forecasting future oil recovery from thatwell. Diagnostics of the various components or the system as a whole mayalso be used to determine problems with the recovery process. Similarly,metering fluid at each well will also provide the opportunity to monitorthe status of the entire oil field, including the recovery device, linesused to pump fluid to storage tanks, and the tanks themselves.

[0016] Displaying, monitoring, and controlling the automated recoverysystem can be done locally at the well or remotely using a desktop orlaptop computer. Communicating with the recovery system can includetwo-wire, wireless technology, or other currently availablecommunication technology. Protocols such as the HART, Fieldbus, Modbus,or other protocols could be used. Further, as will be described ingreater detail below, several automated recovery systems can benetworked together to monitor and control several wells in a field orthe entire field recovery system from one location. While an oilrecovery system is described below, it should be understood andappreciated by one skilled in the art that the teachings of the presentdisclosure could be applied to other types of wells, such as water andgas wells.

[0017] Oil Recovery System

[0018] Referring now to FIG. 1, a system 10 for automating oil recoveryand for metering the amount of oil recovered at a well 12 isillustrated. As shown, an oil recovery system 11 of the presentinvention includes an oil recovery device 14, a control module 16, and ameter 18. The oil recovery device 14 can be any one of several types ofdevices such as a bailing or an air jetting device, which are known oilrecovery devices in the oil recovery business. The concepts of thepresent invention, however, are particularly beneficial when using thecommonly used pump jack or the newly marketed oil extractor by TexasHeritage Oil, Inc. of Georgetown, Tex. to pump fluid to a storage tank35. To fully appreciate the benefits of this invention, the oil recoverysystem described below will include the oil extractor and a pump jack asexamples of oil recovery devices to better describe the presentinvention. It should also be appreciated that the control module couldbe a stand alone module connected to the oil recovery device and/ormeter as illustrated by FIG. 1A, fully integrated into the electronicsof the recovery device, or fully integrated into the electronics of themeter as illustrated in FIG. 1B. Similarly, the oil recovery systemcould be built without a meter. In other words, the system could just becomprised of a pump jack or an oil extractor device and a controlmodule.

[0019] Oil Recovery Device

[0020] The oil extractor currently marketed by Texas Heritage Oil, Inc.includes a canister, which is raised and lowered into the well by a baseunit. Generally, the depth of the canister placed down in the well ispredetermined by tests to determine the top of the oil standing in thewell and the oil/water interface level. Based on this information thedepth setting of the canister is determined. The canister may include apump and a container for collecting the oil. A battery source may alsobe located in the canister to power the pump. When the canister isbrought to the surface it interfaces with a discharge head. As itinterfaces the discharge head, a limit switch is activated to stop themotor (used to bring the canister to the surface) and to start acompressor (used to pressurize the canister and force the oil up througha tube and out the discharge head). Limit switches are also used tocontrol the depth of the canister in the well so that it collects onlyoil. Typically the compressor is timed so that it runs for a period oftime (generally two or three minutes) that is long enough to drain theoil recovered in the canister to a meter, to a flow line and/or to anexternal collection tank. A separate timer may also be set to time therecharging of the battery in the canister before it begins the nextcycle of oil recovery. Timers are also used to limit or control the downcycle time (the total time to lower the canister into the well plus thetime it is left in the well to pump oil in the canister) as well as theup cycle time, which is the time used to raise the canister plus thetime for charging the battery.

[0021] Setting the down and up cycles controls the number of recoverycycles and hence the amount of oil recovered by the oil extractor. Forexample, setting a down cycle for one hour and an up cycle for two hoursmeans that the oil extractor will make eight oil recovery cycles in atwenty-four hour period. In other words, timers are used to determinethe amount of time the canister sits in the oil in the well to allow itto fill and then the amount of time it sits at the surface before itreturns to collect another load. If the canister holds four and one-halfgallons, then thirty-six gallons of oil will be recovered over atwenty-four hour period. This assumes that the canister is sufficientlyplaced in the pool of oil in the well so that the canister fillscompletely before it is brought to the surface.

[0022] A more detail description of the oil extractor is shown anddescribed in U.S. patent application having the Ser. No. 10/106,655entitled “An Apparatus for Extracting Oil or Other Fluids From a Well”by Philip Eggleston and filed on Mar. 26, 2002 and hereby incorporatedby reference.

[0023] The pump jack has been used to pump oil from wells for a numberof years. Examples of these types of pumps are disclosed in U.S. Pat.Nos. 1,603,675 and 2,180,864 and are hereby incorporated by reference.Typically a pump is placed down in the well and is connected to a seriesof rods and tubing. The interconnected rods, which are used to actuatethe pump, are linked to the familiar rocker arms seen in the oil fieldsmoving up and down. An electrical motor is used to drive the rocker armand hence the pump using the rods. The pump sends fluid up the longinterconnected series of tubes to the surface and then to a collectiontank. The common rule of thumb in the industry is to place the pumpsixty feet (typically two sections of pipes and rods) from the bottom ofthe well. A common problem with this rule is that the pump is almostalways placed in salt water, which often exists in oil wells. As aresult, salt water is pumped with the oil. Because of this problem,separator tanks are almost always provided on the surface to separateoil from the water. Salt water is very corrosive and is one of the majorcauses for pumps breaking down. To avail pumping salt water, a test canfirst be conducted to determine the top of oil in the well and then thelevel of the oil/water interface. Once this is determined, the pump canbe placed at a depth where only oil is pumped from the well.

[0024] Control Module

[0025] In the preferred embodiment, the control module 16 consists of amicroprocessor-based controller 20 that provides the functions requiredfor a variety of field automation applications that would enable localor remote monitoring, measurement and data archival, and control of theoil recovery device. For example a Programmable Logic Controller(commonly known as a PLC) could be used. One relatively inexpensive andcurrently available PLC is provided by Unitronics Industrial AutomationsSystems. Unitronics' PLC is has a sufficient processing ability, numberof timers, memory, to control an oil recovery device and has the abilityto provide bi-directional communications. Other controllers are alsoavailable and could be adapted for use in the present application. Suchdevices also include sufficient process inputs and outputs (I/Os) 22 forconnecting the controller to the various electrical components of theoil recovery device. The benefit of multiple I/Os is that it enables themodule to connect to various devices for collecting measured and senseddata for controlling or diagnosing the operation of the oil recoverysystem. In other words, the control module is used to automate therecovery system and allow for remote communication and control of theoperation of the recovery system. For example the extractor unit uses aspool assembly to raise and lower a canister to collect oil in the well.Preferably a proximity sensor is used to monitor the rotation of thespool to measure and control the depth of the canister. Further, thelimit switches, used to detect when the canister has been seatedproperly into the discharge head, are detected by the control module andare used to control both the motor and the compressor to pump the oilout of the canister. Timers within the control module (commonly providedwith most PLCs) can also control the various aspects of the cycle, i.e.when and how long to run the compressor, how long to keep the canisterat the top of the well before sending it down the well for another load,how long to keep the canister at a pre-selected depth to collect oil,etc. The control module also has the ability to tune the recoveryprocess for optimal recovery as will be discussed below.

[0026] Similarly, the control module can be used to automate therecovery system when a pump jack is used as the oil recovery device. Asmentioned above, pump jack recovery devices often use electric motors todrive a rocker arm up and down. The rocker arm in turn is connected tothe rods used to drive the pump in the well. A belt and pulley assemblytypically connects the motor to the rocker arms. Often the belt wearsand breaks without notice and is not discovered until a routinemaintenance visit to the well site. To help automate, control, detect,and diagnose problems with the pump jack, I/Os of the control module arepreferably connected to various electrical devices to control andmonitor the pump jack and the recovery system. For example, a proximitysensor (not shown) is preferably used to measure the motion of one ofthe pulleys of the pulley assembly to detect whether the belt(s) havebroken or are slipping to the point that the flywheel is nottransferring power from the motor to the rocker arm. Further, a powermodule 19 (FIG. 1), such as that sold by CR Magnetics in Fenton, Mo., ispreferably used to determine motor load. Determining motor load isimportant for several reasons. One is the health of the motor itselfAnother is the health of the pump and rods. For example, if the pump orrods break, the motor load will significantly drop and can be detectedby the control module. A drop in motor load could also be symptomatic ofother problems as would be recognized by one skilled in the art. Forinstance, when the well has been pumped dry, the load on the pump shouldalso drop. It is also preferred that I/O of the control module beconnected to the motor for controlling the operation of the motor andthe meter. Connections to other devices to control and monitor pup jacksshould become apparent in light of this disclosure.

[0027] It is also preferred that the control module 16 have acommunications interface 24 that would allow the module tobi-directionally communicate with a local or remote display and controldevice (26,28), i.e. a laptop or desk computer. Interconnection can beaccomplished by either direct wiring 30 or through some form of wirelesscommunication 32 such as cellular technology or radio technology. Insome cases it may be practical, depending on the application and as willbe described below, to have both cellular and radio technologyincorporated in the module. This may further enable other remotelylocated oil recovery systems 34 to be linked together. This will bediscussed in greater detail below. A battery back up 31 is alsopreferably provided to power the module, in the case of a power outage.A relay switch (not shown) could be placed in the main power line andused to monitor or detect power outages by the control module, whichcould then report this condition to a remote user. Using thisinformation, time and money can be saved by allocating resources towells that need attention.

[0028] In addition to monitoring and controlling the oil recoverydevice, the control module has the ability to do diagnostics on theoperation of the oil recovery device and system as a whole. For example,preferably a pressure sensor 19 is provided and in the flow path tomeasure the pressure in the flow line 17 to the collection tank 35.Using the control module to detect the pressure in the flow line andterminate the pumping process can prevent pumping into lines that areclogged because of paraffin build up or into lines that have belownormal pressure indicating that there may be leaks in the flow line. Fordetecting over pressure line conditions, commonly available pressureswitches can be wired and set for detection by the control module.Information resulting from any diagnostics determined by the controlmodule can then be transmitted to a remote user.

[0029] The logic used to program controllers is typicallystraightforward. For example, most PLCs are programmed using ladderlogic, which is a commonly known programming language. Other commonlyused programming languages may also be employed. After understanding theapplications disclosed herein and depending on the control, diagnostics,collected data, communications, etc. that may be preferred, one skilledin the art should be able to easily program the desired logic into thecontroller. An illustrative example of the type of control that ispreferred will be discussed in greater detail below.

[0030] Meter

[0031] For reasons that will become clear, using a meter 18 to measurethe amount of oil recovered at the well by the recovery device is animportant, but not necessarily a required part of automating the systemfor recovery. One benefit of measuring the amount of oil recovered at awell is that the amount of oil recovered can be used to tune therecovery device to maximize the recovery at that well. Another benefitis the ability to track the production and history of production at aparticular well.

[0032] The type of meter used in the present invention will greatlydepend on the application of the oil recovery system. For example, ifthe oil recovery device is a pump jack then there will likely becontinuous flow of fluid pumped from the well. Since the pump ispreferably placed only in oil, a Coriolis flow meter may be morepractical than other types of meters for measuring the amount of oilpumped from the well. A Coriolis flow meter is generally availablethrough a variety of venders. One such vendor, for example, is MicroMotion located in Boulder, Colo. Other types of flow meters are widelyavailable, such as ultrasonic flow meters, vortex flow meters, etc., andmay also be used. Depending on the meter used, preferably (although notrequired) it is configured so that only oil is metered. Measuring andmonitoring fluid flow, even if it includes a combination of oil andwater may be important. For example, to maintain the health of the pump,it is important to determine if it is still pumping fluid. If the pumpis left on after it has pumped the well dry, it is likely that the pumpwill be damaged. Once the history of the well is known, a timer ispreferably used to control the cycles of when the pump should be turnedon and off to efficiently pump fluid from the well as will be discussedbelow.

[0033] Even though the goal is to pump only oil, determining just theright depth to place the pump is not an exact science. For example,water tables can change over time. Thus the ability of the controller totest for the presence of water is useful information and can be used asa signal to turn off the motor of the pump jack. Depending on whichmeter that is used; the presence of water may need to be detectedseparately. A separate sensor can be as simple as a set of probes placedin the flow stream to detect the conductivity of the fluid. For example,if water crosses the two probes, a connection is made to indicate thatwater is being pumped. Otherwise, air or oil in the line willelectrically insulate the probes.

[0034] If, however, an oil extractor were used, then the oil recoveredwould be in cycles or small batches of “oil slugs” flowing in anairline. Measuring these smaller amounts of oil for each cycle is moredifficult, but nonetheless important information for automating the oilextractor as will be discussed below. A Coriolis meter could besimilarly used to measure the slugs of oil, but because of the cost ofthe meter, it may not be practical. Similarly, other meters as discussedabove are available and could be used.

[0035] As an alternative, a special tank meter 36 shown in FIG. 2A thatis under the control of the control module could be used. Becausepressurized air is used to pump oil out of the canister, the oil needsto be separated from the air before it can be measured. As shown, oilpushed by compressed air flows out the discharge head and through aninlet 38 located near the top of a tank 40 (having a known volume) whenthe canister reaches the surface. An outlet 42 for draining the oil fromthe tank 40 is located at the bottom and is closed by a three-way valve44, while the oil fills the tank 40. The three-way valve 44 ispreferably a solenoid valve controlled by the control module 16 (FIG.1). A vent 46 is located at the top of the tank 40 and is connected tothe three-way valve 44 to allow the pressurized air to be exhausted,while the tank 40 is being filled with oil. As the oil slug is beingdumped into the tank, a float level meter 45, connected to the controlmodule 16, detects the level of the oil. The float meter 45 ispreferably similar to float meters used to determine the level ofgasoline in an automobile's gas tank. One skilled in the art wouldappreciate that other types of level indicators could also be used. Inthe preferred embodiment, the meter is a resistive type that varies inohms as the level of oil rises in the tank. Using the level of the oilin the tank (in combination with the known volume of the tank), thecontrol module 16 can easily determine the amount of oil recoveredduring that recovery cycle. Sensor probes 48 connected to the controlmodule are also placed at the bottom of the tank 40 to detect thepresence of water. After determining the amount of oil recovered duringthat cycle, the oil is drained from the tank 40 by switching thethree-way valve 44 to open the drain and close the vent 46. The tank 40can either be re-pressurized by the compressor or pumped out using anexternal pump (not shown) to pump the fluid to the storage tank 35.Other configurations of the tank meter 36 are possible to accomplish theoil/air separation and measurement, as would be appreciated by oneskilled in the art.

[0036] Another method for measuring the fluid in the canister is to usethe control module to automatically pressurize the canister to apredetermined pressure after each recovery cycle before it is emptiedand then measure the amount of time required to reach that predeterminedpressure. The amount of time it takes to pressurize the canister to thatpredetermined pressure has been found to be directly proportional to theamount of fluid in the canister. In other words, referring to FIG. 2B, acanister 51, under the control of the control module 16, is brought tothe surface and engages with the discharge head 49. After engagement, itis pressurized using a compressor 53. Depending on the desiredcompressor used by the recovery system, the compressor 53 can bedirectly controlled by the control module 16 or through a solenoid 55,as shown, connecting a volume of compressed air stored in a pressuretank 57. A valve 59, also under the control of the control module, ispreferably used to seal the canister 51 to allow it to be pressurized tothe predetermined pressure to measure the volume of fluid in it.Alternatively, a pressure restrictor (not shown) could be use topressurize the canister so that a timed measurement could be made.Preferably a pressure switch 61 set at a predetermined pressure is usedto indicate when the predetermined pressure in the canister has beenreached. For example, the pressure switch 61 could be set for 28 PSI.When the predetermined pressure is reached, i.e. 28 PSI in this example,the time it takes to reach that pressure is measured and used by thecontrol module 16 to determine the fluid volume in the canister 51. Oncethe measurement is made, the valve 59 opens and allows the fluid to bepumped from the bottom of the canister 51, up through a tube 63, alongthe inside of the canister 51, and out into a flow line 65. This methodof measuring fluid in the canister provides a cost effective and leastdisruptive method to the recovery process. This technique and method formeasuring volume fluid using pressure is more fully shown and describedin a provisional application filed by Michael Sheldon on Feb. 10, 2003and having the title “Measuring Fluid Volumes in a Container usingPressure.” The teachings of this application are hereby incorporated byreference herein.

[0037] As previously mentioned, a second pressure switch 67 may beprovided and set to a predetermined higher pressure, for example 60 PSIto indicated if the line pressure is approximately equal to or higherthan the second pressure switch setting. Higher pressures in the flowline may indicate that the flow line is clogged. In the alternative, agenerally more expensive pressure sensor for measuring various pressureranges could be used in place of the pressure switches. Using a pressuresensor, low pressures could be further detected in the flow line, whichcould indicate that there is flow line leak. Preferably, the secondpressure switch is located as close to the flow line as practicallypossible for more accurate pressure readings. As one skilled in the artwould appreciate, the flow line pressure switch shown in FIG. 2B islocated in an air supply line to insulate it from the harsher flow lineenvironment. As shown, the pressure of this switch will be slightlyhigher than the actual flow line because of the extra pressure necessaryto push the fluid up and out of the canister.

[0038] A flow diagram is shown in FIG. 2C and used to illustrate thesteps that could be used by the control module for determining thevolume of fluid in the canister and for detecting if water has beenretrieved from the well using the above metering and pressure detectionmethod. The cycle begins when the canister is first detected at the topof the well and properly engaged with the discharge head, step 50. Withthe canister seated at the top of the well, the compressor and a timerare turned on, step 52 and stay on until the pressure switch isactivated, step 54. Once the pressure switch is activated, indicatingthat the predetermined pressure has been reached, the timer is stoppedand the amount of time needed to reach that predetermined pressure isused to determine the amount of fluid in the canister, step 56. Thevalve to the flow line is then opened and fluid is pumped from thecanister, step 58. A timer generally controls the amount of time thecompressor runs to pump fluid from the canister. Depending on the typeand size of the compressor, as well as the amount of backpressure thatmay be present in the flow line, that time may vary. Typically, only acouple of minutes are all that is necessary to pump the canister out tothe flow line. Once the time for running the compressor has lapsed, thecontrol module turns off the compressor and closes the output valve.While the compressor is pumping the fluid from the canister into theflow line, the control module determines if over pressure or high flowline pressure exits, step 60, monitors the second pressure switch. If itis determined that the flow line pressure is too high, the compressor isstopped and a message is sent indicating the condition, step 62. Therecovery device will then wait for instructions, step 64.

[0039] Further, as fluid is pumped from the canister, preferably sensors69 (FIG. 2B), which may be conductive probes, are placed in the flowline and are used to detect if water is present in the canister load,step 66. If water is detected, the control module finishes pumping thecontents of the canister into the flow line and then sends a messageregarding this condition. Until instructions are sent back to thecontrol module, the recovery devices sits idol, step 68

[0040] If neither of the above two conditions exist, the module willwait until the compressor has timed out before starting the nextrecovery cycle, steps 70 and 72. Thereafter, a record of the volume offluid recovered, including the time and date when it was retrieved iscreated and set to a remote operator, steps 74 and 76. Alternatively,this record could be stored by the control module and retrieved by theoperator or remote user if requested. Similarly this information, aswell as various conditions and states of operation of the recoverydevice, can be displayed on a display panel of the control module (notshown) at the well site.

[0041] Oil Recovery System

[0042] Automatic control of the oil recovery system is accomplished byconnecting the control module to the motor and the various switches tooperate and control the oil recovery device as well as the meter. Theactual connections to the various switches are not shown because theywill depend on the particular oil recovery device and the variousaspects of the control device that the user wishes to operate andmonitor. But in view of the discussions for control herein, one skilledin the art should easily understand how to make such electricalconnections to monitor and control the various actions of the oilrecovery system.

[0043] Referring now FIG. 3A a flow diagram is shown and used toillustrate a control cycle of the oil recovery system using an oilextractor. While the description below describes the preferred methodfor controlling the operations of such an oil recovery system, it shouldbe appreciated by those skilled in that art that other methods androutines could be used to essentially accomplish the same or similarautomated control.

[0044] As mentioned above the depth of the canister is predetermined anda relay switch is set before the canister is sent down into the well. Toinitiate the recovery cycle, the control module starts the motor tolower the canister down into the well and starts timer 1 to measure thetime required to get to the desired depth, step 78. As one alternative,the timer could be used to control the motor, if the rate of the descentis known. Using the timer to control the motor would enable the user toeasily change the depth of the canister without resetting the relaylimit switch. That limit switch could then be used as a back up maximumdepth switch, should something go wrong. The actual depth could also bedetected by using a sensor, such as a proximity sensor that detects therevolution of a pulley used to lower the cable/canister down the well.In other words, the length of cable used could be metered. When thepreferred depth is reached, the control module automatically turns offthe motor.

[0045] At the desired depth, timer 1 is turned off and the amount oftime it took for the canister to reach that depth is recorded by thecontrol module 16, step 80. This information may be used later asdiagnostic information to determine if problems existed with thecanister descending down into the well. When the canister reaches thedesired depth, timer 2 is started to control the time that the canisterwill stay in the well, step 82. Typically 3 or 4 minutes is all that isneeded. When that timer times out or when that timed cycle is completed,the control module activates the motor to bring the canister back to thesurface. Timer 3 is initiated to measure the required time to bring thecanister back up to the surface, step 84. A relay switch (as describedabove) is used to detect when the canister interfaces with the dischargehead. At that time the motor is turned off and the amount of timeindicated by timer 3 is recorded, step 88. The time recorded for timer 1and timer 3 can then be compared to see if there are any abnormalitiesor problems. At that time, the control module also activates thecompressor, which pressurizes the canister and causes the oil to pump upand out of the discharge head of the extractor device. From thedischarge head, the oil dumps into the tank meter as described above,step 90. Timer 4 is activated to control the time that the compressor ison. Typically 1 or 2 minutes is all that is required to pump the oilfrom the canister into the tank meter. While the oil is emptying intothe tank, it is preferred that the control module constantly monitorsthe oil level in the tank, step 92. The canister has been emptied whenthe oil level ceases to rise. The compressor could be optionally turnedoff by the control module or left to run for its timed compressor cycledetermined by timer 4. The control module may also measure the voltageof the battery while the canister is connected to the discharge head. Ahistory of voltage measurements for every cycle could be stored andevaluated to determine the health or condition of the battery and/or itremaining battery life. Preferably the battery charger starts torecharge the battery while the canister is in the discharge head duringeach cycle, steps 94 and 96.

[0046] Once all the oil has been dumped into the tank, the volume isdetermined, recorded and time stamped, step 98. A test is also conductedto see if any water was dumped in the tank, step 100. These results arepreferably recorded and time stamped. The three-way valve 44 (FIG. 2A)is then opened to drain the oil from the tank, preferably usingpressurized air from the compressor. Using timer 5 the duration of thepressurized air needed to empty the tank can be controlled, step 102. Ifno water was found in the tank, the control module turns off the batterycharger and returns to the beginning of the recovery cycle steps 104 and106. If water is detected the control module notifies the user/operatorand terminates the recovery cycle until the user reinitiates it and/oroptionally automatically resets the recovery device to recover oil at arate approximately equal to the oil being recovered by the well. Thiswill be discussed in more detail below.

[0047] While the above describes different timers for different events,it should be understood by one skilled in the art that the same timercould be used for different purposes. Also, depending on the user, othercontrol or monitoring features could be built into and/or currentlyshown operations removed from the operating flow diagram describedabove. For example, ambient temperature and/or pressure used to pump theoil could be measured.

[0048] For a pump jack, the control module would not have to monitor andcontrol all of the switches and timers that are necessary for the oilextractor. Generally, monitoring and controlling the oil recovery systemwould be a simpler matter. For example, as illustrated in FIG. 3B, therecovery cycle begins with the control module turning on the motor,causing fluid to be pumped to the meter where the volume of oil ismeasured, recorded and time stamped, step 108. A timer 1 is started tomeasure/control the duration of the recovery cycle. Since it ispreferred that the pump is placed at a much higher level in the well topreferably pump only oil, the duration that the pump would run would bea function of the amount of oil that has accumulated in the well sincethe last time it was pumped and the well's oil recovery rate. This willbe discussed in greater detail below. As it is pumped, the fluid istested for the presence of water or “fluid pounding,” step 110. Becauseof the possibility of changing water tables, or selecting the properdepth for placing the pump, it is always possible that water could bepumped. Fluid pounding occurs when the level of fluid to be pumped isless than the amount of fluid that can be readily handled by the pumpingequipment, which could result in damaging the pump. Fluid pounding couldbe easily determined by measuring the motor load, which will bedifferent for pumping fluid than for pumping air. If water or fluidpounding is detected then the control module could turn the motor off,stop timer 1, record the pumped time, and then notify the user. Timer 1may then need to be reset to a new pump time cycle steps 112 and 114.Otherwise the pump continues its operation until the recovery cycletimer 1 clocks out, step 116. Once that occurs, the controller stops themotor and begins a time out timer 2 set to the recovery rate of thewell. At the end of that time out, the recovery cycle begins a newcycle. In other words, the pump jack could be turned on by the controlmodule for 20 minutes and then turned off for the remainder of the dayas an example, depending on the well's oil recovery rate, step 118.

[0049] Tuning

[0050] In order to efficiently pump oil from a well it is useful todetermine the recovery rate of the oil seeping into the well, i.e. oilrecovery rate of the well. Generally, the expected rate of oil recoveryfor any particular well can be determined from the pumping history ofthe well. That rate is often determined by the amount of oil recoveredusing old pumping techniques that include pumping water, so it is notnecessarily reliable information. Further, water tables change overtime. As a result, the amount of oil seeping into the well can change.Still further, since it is preferred that the pump is placed in the wellso that only oil is pumped, there is less hydrostatic pressure in thewell used to pull oil into the well, so the amount of oil available topump could change. As a result, the best way to measure that recoveryrate is to place the pump for both the oil extractor and the pump jackat predetermined depth in the well and set the recovery device torecover oil faster than the expected rate of oil recovery. For the oilextractor this means that for each recovery cycle the canister wouldreturn to the same depth in the well. Preferably this depth isdetermined by first determining how much standing oil there is in thewell. For example, if the top of the oil in the well is found to be at1327 feet and the water/oil interface is at 2197 feet, then 870 feet ofstanding oil exits in the well. Below 2197 feet is water. Using thisinformation, the pump is preferably placed in the oil so that only oilis pumped. By pumping at a faster than expected recovery rate, theamount of oil recovered will decrease to a constant amount once the oilabove the pump has been pumped down. That constant amount will be therecovery rate for that well. Over time that rate is likely to change asmentioned above. Accordingly, it is preferred to set the recovery rateof the oil recovery device to a rate slightly higher than the determinedrecovery rate and to monitor the recovery rate over time. As therecovery rate increases or decreases, the recovery device can be tunedaccordingly to make it more efficient. This can be accomplished by usingthe control module to increase/decrease the number of oil recoverycycles for the oil extractor or increasing/decreasing the time the pumpjack is operated.

[0051] Automating the recovery device has other tuning advantages foroptimizing the recovery process. For example, the extractor unit can betuned to optimize its recovery rate as illustrated by the control flowdiagram shown in FIG. 4. Increasing the chances that a full load isrecovered with each cycle can optimize the extractor unit. For example,by measuring the amount of fluid recovered, as described above, thecontrol module can lower the canister further into the well on the nextcycle. If the volume is less than a predetermined amount, then thecanister is lowered by a predetermined amount in the well, steps 120,122, and 124. Preferably, a determination is made as to whether thecanister is at a maximum level so that it retrieves only oil, step 126.If not then the control module will lower the canister by apredetermined amount to ensure that the next load is full, step 128. Ifthe level of the canister has already reached the maximum level, thetime that the canister is at the top of the well can be increased toaccount for the recovery time of the well when a less than predeterminedload is detected, step 136. Avoiding partial load saves time and energy.

[0052] Similarly, as would be appreciated by those skilled in the art, apump jack can be more efficient if a meter is used to determine theamount of fluid recovered and timing its operations to optimizerecovery.

[0053] Communication Networking

[0054] Typically an operator in the oil fields manages leases withseveral oil wells. In accordance with the teachings of the presentdisclosure, preferably each well is equipped with a well recovery systemdescribed above (138-143) as illustrated in FIG. 5. As one skilled wouldappreciate, often these fields are in remote and not easily accessibleareas. At the surface of each well, a series of flow lines/pipes 144 isoften used for enabling the recovery devices at each well to pump fluidto one or more storage tanks 146. In some cases, a storage tank may beassigned to only one well (not shown). To effectively manage thesewells, in addition to automating the recovery device as described aboveit is preferred that each recovery device be equipped with a two-waywireless communication device 32 for creating a communication network toenable data collected at each well to transmitted to an operator'scomputer 148. For example a wavecom modem can be connected directly tothe control module to enable wireless cellular communication to eachrecovery device. Alternatively, a two-way radio is connected directly tothe control module and enables radio communication to each recoverydevice. Radios having a radius of communication between 5 to 10 milesare commonly available, relatively in expensive, and particularly suitedfor this application. Using this data, the operator can remotely monitoror control each recovery device as necessary, thereby avoidingtime-consuming trips to monitor and control the wells. It is alsopreferred that the storage tank 146 be equipped with a two-way wirelesscommunication device 32 and a meter 150 that measures the fluid level inthe tank 146. A control module 152, similar to that one shown anddescribed with reference to FIG. 1 above could be used to operate thecommunications device 32 and the meter 150 from the tank. Benefits ofputting a control module on the tank include notifying the operator orowner of the level of the fluid in the tank to prevent over flow and toschedule pickups at desired times. In potential overflow conditions, thecontrol module could be programmed to shut down the pumps feeding intothe tank. Placing a control module at the tank also provides theopportunity to make that control module the master device forcommunication to the operator (as will be described in more detailbelow) since the tank may be more likely to be located in a place,facilitating dial up telephone line connection as an alternative towireless cellular connection.

[0055] In one embodiment, each recovery system is preferably equippedwith a radio transmitter or cellular communications as described abovethat would enable communications back and forth between the operator andeach recovery device. Radio transmitters and cellular communicationsequipment for this purpose are commonly available. Wireless webtechnology is also available. For example, Aeris.net of San Jose Calif.offers products that provide two-way wireless connectivity and controlof remote intelligent devices.

[0056] In an alternate embodiment, the one recovery device could bedesignated as a master recovery device for communication with theoperator. The remaining recovery devices would be designated as “slave”recovery devices that communicate with the operator through the masterrecovery device. In some cases, because of the remoteness of some of thewells, the radio transmitters could be configured to use other radiotransmitters located on closer recovery devices to communicate with amore remote master recovery device. In other words, the transmission ofdata from one slave recovery device may use another slave recoverydevice (known as a repeater) to communicate with the master recoverydevice if it is not close enough to directly communicate with it. Themaster recovery device would preferably have cellular communications forremotely communicating with the operator anywhere in the world.

[0057] The type of information that would be useful to the operatorincludes information for monitoring the operation of the devices, formetering the amount of oil as it is being produced at each well, and forperforming diagnostics for each device and/or system of devices(including performance of various components of the device, the deviceas a whole, or communications with the devices). Data could beautomatically stored by the control module and thereafter automaticallysent to an operator or upon the operator's request. Based on thisinformation, the operator or user would then be able to change theoperating instructions, such as change the recycle recovery time asdescribed above, raise or lower the canister in the well, reset thedepth of the canister, or shut down the recovery system for servicerepairs. Similarly a business plan could also be developed forrecovering oil at each well and charging for those services based on theamount of oil recovered at that well or by leasing such a recoverysystem at each well. A service business plan could also be developed formaintaining the operation of the devices or the oil field as a whole.For example, by being able to meter the amount of oil recovered at eachwell, a business method could be developed for leasing the oil extractorand charging only for the amount of oil recovered at that well by thatextractor. Production rates, histories, invoices, etc. could then besent electronically to the well owner/operator. Further, using webbrowser technology, the owner/operator of the well or oil/gas fieldcould view the operation of the various devices remotely, withoutinterfering with the operations.

[0058] Diagnostics

[0059] By providing a communications network described above, there areseveral types of diagnostic routines that can be preformed both at thedevice. The results of these diagnostic routines can be automaticallytransmitted to the owner/operator by the control module to either theremote operator's computer or to an operators cell phone (not shown),allowing for quick responses. Preferably, the operator's cellular phoneis configured to send requests or commands to the recovery devices.Alternatively these results can be sent upon request by theowner/operator communicating with the devices. A few of the possiblediagnostic routines that could be preformed by the control module willbe described below. However, is should be clear to one skilled in theart that several other diagnostic routines could be created to evaluatethe performance of the recovery device, the recovery system, or thecommunications to the devices.

[0060] One important diagnostic is to test for leaks in the lines 144(FIG. 5) connecting the oil recovery system 11 to the storage tank 146.Often leaks occur in these lines and there is no way of finding theseleaks until physical inspections reveal the spillage or environmentaldamage. With the present system, tests can now be preformed to testthese lines by determining the metered amount of fluid pumped into thelines by the various recovery devices and then comparing that amount tothe amounts received in the tank. By controlling the recovery device,the flow pattern in each line can be controlled and a determination ofthe health of the flow line connecting each recovery device to the tankcan be determined. For example, in succession all but one of therecovery devices could be turned off. The amount of fluid pumped by thatrecovery device could then be compared to that amount received at thetank using the level meter 108. Other combinations of pumping by thedevices and measuring the amount received by the tank could also bedone.

[0061] Another preferred diagnostic test includes testing the accuracyof the meter. If a business charges for fluid pumped at the wells,reliability and accuracy of the meters are critical. There are severalways to test the meter. One way is to test the meter reading at therecovery device and compare it to the amount received at the tank asindicated by the level meter 150 at the tank. Since it is preferred thateach metered amount is time stamped at the well, providing a time stampof when fluid is received and the amount received can be used todetermine relative accuracy of the meter at the well. Another way toverify the accuracy of the metering system is to put a three-way valve(not shown) between the meter and the line 144 used to deliver the fluidto the tank. The T-valve would allow a field operator or recovery deviceinspector to randomly test the amount of fluid measured by the meter andcompare it against the time stamped amounts recorded, much in the sameway gas pumps at gas stations are monitored.

[0062] Other diagnostic tests that would be important include theoperation of the recovery device, such as monitoring the well being ofthe motor used to operate the recovery device and the compressor of theoil extractor. One test that could be preformed by the controller or bythe operator collecting data from the recovery device could includecomparing the history of the up/down time of the canister for the oilextractor device or the number of pumping cycles of the pump jack. Aslow down in either would indicate a drag on the system, which couldmean motor fatigue. Tests could be performed to test the operation ofthe compressor for the oil extractor by measuring the pressure build upin the tank meter with the vent and drain closed. Monitoring anddetermining increasing pressures needed to drain the canister and themeter tank could be symptomatic of pressure leaks. Other diagnosticswould include detecting the motor load to detect fluid pounding for pumpjacks or when the top of the fluid is reached by the canister of the oilextractor for determining the level of fluid in the well. Thisinformation could also be used to tune the recover of the recoverysystem.

[0063] It should be understood by one skilled in the art that severalmodifications to the system disclosed above could be made withoutdeparting from the spirit and scope of the present invention. Forexample, there are various types of controllers and communicationdevices available in the market that could be configured to operate inaccordance with the teachings described above. The number of I/Os neededto make digital or analog connections will vary depending on therecovery device that is used and the type of data to be collected. Forexample, sensors could be placed on the pump jack to detect the motionof the rocker arm for detecting if the rod break, detect if the cable orbelt between the pump and the motor fail, etc. Further, the controlmodule could be independently powered by solar or battery supplies or beconnected to available power lines. A battery backup system could alsobe provided to protect the settings and stored data of the recoverysystem. Diagnostics described above as well as other diagnostics couldbe done at the control module and results sent to an operator orperformed by the operator remotely from the recovery system. Alarms andalerts could be built into the system to warn the operator of certainevents. Other benefits and options could be built into theabove-described system and should become apparent in view of theteachings above.

[0064] Although certain apparatus constructed in accordance with theteachings of the invention have been described herein, the scope ofcoverage of this patent is not limited thereto. On the contrary, thispatent covers all apparatuses, methods and articles of manufacture ofthe teachings of the invention fairly falling within the scope of theappended claims either literally or under the doctrine of equivalents.

In view of the above discussion I claim:
 1. A fluid recovery systemcomprising: a. a recovery device for retrieving fluid from a well; b. ameter connected to the recovery device for receiving flluid from therecovery device and measuring the amount of fluid recovered; and c. acontrol module for controlling the operation of the recovery device andthe meter.
 2. The fluid recovery system of claim 1 wherein the controlmodule is integrated into the recovery device.
 3. The fluid recoverysystem of claim 1 wherein the control module is integrated into themeter.
 4. The fluid recovery system of claim 1 wherein the recoverydevice is extractor.
 5. The fluid recovery system of claim 1 wherein therecovery device is jack.
 6. The fluid recovery system of claim 1 whereinthe control module stamps the measured amount of fluid recovered by therecovery device.
 7. The fluid recovery system of claim 1 wherein thecontrol module includes a communications interface for transmitting datato and from fluid recovery system.
 8. The fluid recovery system of claim7 where in the communications interface is wireless communications. 9.The fluid recovery system of claim 8 wherein the wireless communicationspermits remote monitoring and control of the fluid recovery system. 10.The fluid recovery system of claim 1 wherein the control modulediagnostic operations and communicates the results of those operationsto a user.
 11. The fluid recovery system of claim 1 wherein the meter isa tank to separate air and fluid.
 12. The fluid recovery system of claim1 wherein the meter further include sensors for detecting water.
 13. Thefluid recovery system of claim 1 wherein the fluid recovered is oil. 14.The fluid recovery system of claim 13 wherein the control module tunesthe oil recovery rate of the recovery device to recover oil at a rateapproximately equal to the recovery rate of oil in the well.
 15. A fluidrecovery network comprising: a. two or more recovery systems, eachhaving i. a recovery device for retrieving fluid from a well; ii. ameter connected to the recovery device for receiving fluid from therecovery device and measuring the amount of fluid recovered; iii. acontrol module for controlling the operation of he recovery device andthe meter; and iv. a communications interface for transmitting data toand from the recovery system; b. a storage tank for storing fluidretrieved by the recovery systems; and c. flow lines interconnecting thetwo or more recovery systems and the storage tank.
 16. A metercomprising: a. means for measuring fluid; b. a control module forcontrolling the operation of the meter and other devices connected tothe meter; and c. a communications interface for communicating data toand from the meter.
 17. The meter of claim 16 wherein the control moduleincludes diagnostic routines for the meter and the other devices. 18.The meter of claim 16 wherein the meter is placed at a well formeasuring fluid recovered from the well.
 19. The meter of claim 16wherein the communications interface includes wireless communications.20. The meter of claim 16 wherein the meter is a Coriolis flow meter.21. The meter of claim 16 wherein the meter is a tank meter forseparating air and fluids for measuring the fluid, the tank metercomprising: a. a tank having an inlet for receiving air and fluid, adrain for emptying the tank of fluid, and a vent for air; b. at leastone valve for opening and closing the drain and vent; and c. level meterto measure the fluid in the tank.
 22. The tank meter of claim 21 whereinthe valve is a three-way valve.
 23. The tank meter of claim 21 furthercomprising a sensor for detecting the presence of water in the tank. 24.A method of recovering fluid from a well comprising the steps of: a.recovering fluid from a well using a pump jack or oil extractor; b.measuring the amount of fluid recovered by the recovery system; and c.communicating the amount recovered at the well by the recovery system toan operator.
 25. A method of doing business comprising, a. recoveringfluid at a well; b. metering the amount of fluid recovered; and c.charging a fee based on the amount of fluid recovered.
 26. A fluidrecovery system comprising: a. an oil extractor device for retrievingfluid from a well; and b. a control module for controlling the operationof the recovery device and having a communications interface fortransmitting data to and from the oil extractor device.
 27. The fluidrecovery system of claim 26 wherein the data transmitted from the oilextractor device is diagnostic information.
 28. The fluid recoverysystem of claim 26 further including a meter connected to the oilextractor for receiving fluid and measuring the amount of fluidrecovered by the oil extractor.
 29. The fluid recovery system of claim26 wherein the control module time stamps the measured amounts of fluidrecovered.
 30. A fluid recovery system comprising: a. a pump jack forretrieving fluid from a well; and b. a control module for controllingthe operation of the recovery device and having a communicationsinterface for transmitting data to and from the pump jack.
 31. The fluidrecovery system of claim 30 wherein the data transmitted from the oilextractor device is diagnostic information.
 32. The fluid recoverysystem of claim 30 further including a meter connected to the oilextractor for receiving fluid and measuring the amount of fluidrecovered by the pump jack.
 33. The fluid recovery system of claim 30wherein the control module time stamps the measured amounts of fluidrecovered.
 34. A fluid recovery system of claim 30 further comprising abi-directional communication device that enables an operator to monitorand control the recovery device remotely.
 35. The fluid recovery systemof claim 34, wherein the bi-directional communications device is a modemfor cellular connection.
 36. The fluid recovery system of claim 34,wherein the bi-directional communications device is a radio.
 37. Thefluid recovery system of claim 34 wherein the communications deviceincludes both a bi-directional communications radio and a modem forcellular connection.